Field of the Invention
This invention generally relates to a position sensing device. More specifically, the present invention relates to a position sensing device that scans a sensing area with test light and senses the position of a sensing object by detecting reflected light and/or scattered light from the sensing object within the sensing area. Also, the present invention relates to a spatial input device that senses input to a spatial image formed within a space, and a processor.
Background Information
Generally, a position sensing device has been proposed in which a specific area is scanned and the movement of a hand, finger, or the like within this specific area is sensed (see, for example, Japanese Laid-Open Patent Application Publication Nos. 2013-80516 (Patent Literature 1) and 2014-154063 (Patent Literature 2)).
With Patent Literature 1, light source units that emit illumination light that is scanned over a coordinate input plane are provided at two locations, recursive reflection is received from a recursive reflective member attached to a coordinate support (such as a finger or an electronic stylus) inserted into the coordinate input plane, and the position (coordinates) of the coordinate support is sensed from the timing at which the reflected light is received.
With Patent Literature 2, a specific scan area is scanned with a detection wave (such as infrared light with a wavelength of 780 nm), an input device is attached to the user's finger, and the infrared light is detected with a light receiving element provided to the input device, thereby detecting that the input device is within the operation area, and a piezoelectric element is vibrated to notify the user that the input device is within the scan area.